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Conference Object Citation - WoS: 1PRODUCTION OF SILVER LOADED PHOTOCATALYTIC TIO2 POWDERS BY BALL MILLING(Tanger Ltd, 2011) Aysin, Basak; Park, Jongee; Ozturk, AbdullahThe present study was undertaken to improve photocatalytic efficiency of TiO2 powder by silver doping and/or particle size reduction through mechanical ball milling. A planetary ball mill was employed to reduce the particle size of TiO2 powders to nanoscale and silver loading to TiO2 powders. Silver nitrate was used as silver source to obtain about 1% Ag load. Slurry taken from ball mill was separated by centrifugal separator into nano and micro sols. Separated nanosol was taken into the furnace to be dried at 103 degrees C and calcined at 400 degrees C for 1 hour to assist silver loading. X-Ray powder diffraction (XRD) was employed to identify the crystalline phases present in the powders produced. XRD results revealed that doped TiO2 powders were consisted of only anatase phase of TiO2. Changes in lattice parameters of TiO2 structure after doping were determined also by XRD. Scanning Electron Microscope (SEM) and particle size analyzer were used for examining the size reduction effect of ball milling process. Photocatalytic performance of the powders was evaluated by Methylene Orange (MO) test under UV light illumination using UV-Spectrophotometer.Conference Object Citation - WoS: 2Citation - Scopus: 4Influence of Boron And/Or Zirconium Doping on Morphology and Optical Properties of Titania(Tanger Ltd, 2011) Kapusuz, Derya; Park, Jongee; Ozturk, Abdullah; Metallurgical and Materials EngineeringSol-gel derived B (boron) and Zr (zirconium) doped TiO2 (Titania) nanoparticles were synthesized. Microstructural, photocatalytic and crystallographic properties of the doped particles were investigated. Highest photocatalytic activity was achieved by 10 wt% Zr doping. 5 wt% doping was the optimum value for effective B doping. B ions were found to form oxygen vacancies behaving as interstitial defects whereas Zr ions substituted Ti4+ ions in the lattice.Conference Object Predicting the Topology of the Bending Corner in Bending of Ultra High Strength Steels Through Finite Element Analysis(Tanger Ltd, 2019) Cetin, Baris; Billur, Eren; Baranoglu, Besim; Toptas, Ugur; Alic, Ozgur; Manufacturing Engineering; Automotive EngineeringIn bending of plates, unlike the case of sheet metal forming, a 3-D stress state is valid. Moreover, apart from the some very specific cases, the plane strain assumption is not appropriate either. Therefore; bending of thick ultra-high strength steel (UHSS) plates is a deformation process where 3-D stress and strain states exist in general. This study basically focuses on the prediction of the bending corner topology with non-linear finite element analysis method, since the laser-cut edges of the UHSS are particularly prone to edge cracking during bending operation. Within the scope of this study, an experimental set-up is designed which consists of bending tools and a servo mechanical press. The samples were bent by means of this set-up in an air-bending operation up to 90 degrees. This experimental work was followed by optical scanning measurements. And finally, the FEA results and the scanning data were compared in 3-D space. The results showed good correlation. As a future study, the 3-D strain field of the bending corner will be tried to be measured by a professional digital image correlation (DIC) system which could probably give more precise data when combined with the data from FEA.
